According to most concrete construction contractors, site-mixed concrete is on its way out in favor of ready-mix. In fact, almost 60% of all concrete produced is now of the ready-mix variety, and it’s no wonder considering the advantages the ready-mix type has over site-mixed. From faster working conditions and better quality to fewer materials and lower cement usage overall, ready-mix concrete seems poised for a complete takeover when it comes to all but the very biggest construction projects. So, whether you’re planning to build a road, a bridge or a building, you’re most likely using ready-mix concrete, but there are few different kinds depending on how and where it is mixed. Let’s break down the three most common types.
1. Transit mixed concrete
Also known as truck-mixed or dry-batched concrete, this type of ready-mix concrete is mixed entirely within the truck mixer it is transported in, and there is no plant mixer involved in the process. Transit mixed concrete is also delivered in one of three ways.
- If it is mixed at the concrete yard and then delivered to the job site, the materials are loaded into the mixing drum and then rotated at a slow, agitating speed until arrival where the mixing is completed.
- If it is mixed in the yard before delivery to the job site, the drum is rotated at a fast speed before slowing down to an agitating speed for actual transport.
- If it is mixed in transit, the drum is rotated at a medium speed while being driven to the job site where it is slowed down to an agitating speed upon arrival.
2. Shrink mixed concrete
This type of ready-mix concrete is only partially mixed at the central plant before being loaded into truck mixers where the rest of the mixing process takes place. The amount of mixing required in the drum of the truck mixer depends on how much the material was originally mixed at the central plant. A slump test for uniformity should be completed upon arrival at the job site to ensure quality.
3. Central mixed concrete
Concrete from a central mix facility, sometimes known as a pre-mix or wet-batch plant, is mixed thoroughly before being loaded into the drum of a mixing truck. Once inside, the drum may be rotated at a slow speed for agitation purposes only. If the transportation distance is not too great, this type of ready-mix concrete can also be loaded into a non-agitating vehicle, such as a dump truck.
Make sure to ask your professional concrete construction contractors in Michigan about which type of ready-mix concrete is appropriate for your next big commercial construction project.